In the field of reproduction apparatus, the trend has been to incorporate more and more features into a single apparatus to increase its capability of handling a greater variety of copying jobs. Thus it has been proposed to provide electrophotographic apparatus which produces either single image simplex or single image duplex copies during a single pass of the copy sheet through the electrophotographic apparatus. Such an apparatus, for example, is disclosed in commonly assigned U.S. Pat. No. 4,191,465 issued Mar. 4, 1980, for "Apparatus for Producing Simplex Or Duplex Copies," by E. E. Boase et al. It has also been proposed to provide electrophotographic color copiers in which multiple images are transferred in registration to one side of a copy sheet during a single pass of the copy sheet through the copier. Such a copier, for example, is disclosed in commonly assigned U.S. Pat. No. 4,251,154 issued Feb. 17, 1981, for "Electrophotographic Color Copier," by M. J. Russel. As disclosed, the apparatus includes a movable image transfer member adapted to receive related transferable color separation images in non-overlapping image areas, and a transfer mechanism mounted adjacent to the image transfer member to transfer the separation images into registration onto one side of a copy sheet. The copier includes register rollers disposed between adjacent transfer stations which remove a copy sheet from contact with the image transfer member and return it in registration with the next image on the transfer member at the next transfer station. Instead of the multiple transfer stations and multiple register rollers disclosed in the latter patent, it has also been proposed to use a single copy roller and single transfer station for multiple image transfer to a single copy sheet. Thus, in U.S. Pat. No. 3,690,756 issued Sept. 12, 1972, for "Color Xerography," by W. A. Smith, an embodiment of color copier is disclosed in FIG. 4 in which a sequence of color separation images of the same original are formed on a photoconductive belt and the images sequentially transferred in registration to a sheet of support material by means of a copy roller and corona transfer device. Although the devices disclosed in these patents may be suitable for the uses for which they are intended, there has been a need for reproduction apparatus which is capable of not only producing single-image simplex or duplex copies of an original during a single pass of a copy sheet through the apparatus, but which is also capable of forming multiple images of an original on a copy sheet in either the simplex or duplex mode during a single pass.